Manufacture of celluloid.



UNITED STATES PATENT OFFICE.

CARL GUSTAV HAGEMANN AND FRIEDRICH OTTO CORNELIUS ZlMMER-' MANN OF LUDWIGSHAFEN, GERMANY.

MANUFACTURE OF CELLULOID.

SPECIFICATION formingpart of Letters Patent No. 657.535, dated September 11, 1900.

Application filed J'1i1'1e25, 1898i Serial No. 684,503. (No specimens) To (ZZZ whom it may concern-P Be it known that We, CARL GUSTAV HAGE- MANN and FRIEDRICH OTTO CORNELIUS ZIM= MERMANN, of Ludwigshafen-on-the-Rhine,

Germany, have invented certain new and useful Improvements in the Manufacture of Celluloid; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appert'ains to make and use the same.

This invention relates to the manufacture of celluloid, which, as is well known, consists, essentially, of nitrocellulose and camphor,

which latter imparts the required plasticity to nitrocellulose. It is also well known that cellulo1d 1s a highly-combustible substance which is not only readily ignited, but burns cellulose a hydrate or hydroxid of a metal,

and this is best eifected by incorporating with a solution of nitrocellulose a concentrated solution of the salt of a metal, then precipitating from said salt the hydroxid by chemically decomposing the same by treating the compound with a correspondingly-concentrated solution of a salt of a metal of the alkalies having the property of neutralizing the compound, as a solution of caustic soda, after which the solvent for the nitrocellulose as Well as the soluble products formed under the action of the precipitant are removed, the remaining compound being then dried and gelatinized in the usual manner, with or without the addition of camphor. In some cases we also incorporate with the compound an oleaginous body, preferably castor-oil, when we desire to obtain a smooth and duetile final product, the oil being incorporated with the nitrocellulose solution before the incorporation therewith of the hydrate or hydroxid of a metal. In order to remove all danger of explosion, we convert the nitrocellulose while wetinro cell uloid oriuto a celluloidal body, which we have called hydrocellite, as will hereinafter appear. We are thus enabled to save the expense involved in first drying the nitrocellulose.

t In carrying out our invention we dissolve the nitrocellulose while wet (containing fifty per cent, more or less, water) in a suitable solvent, as acetone, so as to form a semifluid or more or less. doughy mass. With this mass we incorporate a concentrated aqueous solution of a salt of a metal-as, for instance, a sulfate of alumina-which may be done by trituration, kneading, or otherwise, whereby we obtain a homogeneous plastic transparent compound. With this compound we incorporate a concentrated solution of a salt of an alkali metal having the property of neutralizing such compound-as, for instance, caustic sodawhich is preferably gradually added to and incorporated with the compound by trituration, kneading, or otherwise until the compound is neutralized, which can readily-be ascertained by the fact that the mass becomes almost suddenly more or less crumbly or friable, while the hydroxid of alumina is precipitated, and thus molecularly and quantitatively combined with the nitrocellulose, as clearly shown by the following forcombined nitrocellulose and hydrate of alumina in a more or less gritty or friable condition, While the solvent and sodium sulfate can be removed from the waste liquor by distillation and crystallization, respectively. The com pound of nitrocellulose and hydrate of alumina obtained as described is then dried, gelatinized in the usual manner by means of acetone or a solution of cam phor in acetone ora solution of camphori-nalcohol or the likep'and then molded into any desired forms The degree of plasticity of the' final product depends, of course, upon the proportion of camphor incorporated therewith. On

the .other. hand, in the ,absence of "camphor the final product is a veryh ardone, possess-T If it? ing but little plasticity when heated. is. desired to obtain a very smooth ductile final product, an oleaginousbody, preferably I castor-oil, is mixed with the solution of nitrocellulose before'the' incorporation therewithf of the hydrate :erh ydrox id of a metal; In the following examples we have givenproportions of ingredients which have yielded"- excellent results, the parts being given by" weight: I

" Hydrocelli-te'without camphor or oil: 'n'itro cellulose, seventy parts; hydrate'of alumina, thirty parts.

Hydrocellite without oil: nitrocellulose,

fifty-six parts; hydrate of alumina, twen tyoil, ten parts.

four parts; camphor, twenty art-s. v

Hydrocellite' without camphor: nitrocellulose, si-Xty three parts; hydrate of alumina,

twenty-seven parts; Castor-oil, ten parts. Hydrocellite with camphor and oil:;nitrocellulose, fi'fty parts; hydrate of alumina,-

twenty parts; camphor,-twenty parts; castor- The proportions of concentrated solutions of the salt of alumina and caustic sodaare determined by well-known stoicheiometric rules, due consideration being ha'dof thedegree of purity of the chemicals. f

Hydrocellite can becolored in the same manner as celluloid, as the hydrate of alu-. mina fixes colors.

In the process described and as hereinbefore stated 'hydroxids of "other metals can be used and intimately incorporated with-the nitrocellulose, provided, of course,the salts of the metals can be readily dissolved, 'while very attenuatedsolutions do not readily combine with the nitrocelluloseb From what has been said it will readily be seen that hydrocellite has very material advantages over celluloidas, for instance, its

comparatively-low degree of inflammabilityand itspossibility of varying the density of the product and its degree of hardness within very wide limits.

The manufacture'of the hydrocellite is free from danger, because the nitrocellulose is worked up while in such a wet condition that itcannot even be ignited, much less exploded, while the drying is ef-" 'fectedafter incorporation therewith of a salt of a metal which renders the compound pracnecessary to dry the same, so that the drying -tieally non-explosive at the degree of heat operation is also not fraught with danger.

. Finally,the cost of the hydrocellite is very materially less than that of celluloid, while the range of use of the former is equally asgreat and in fact greater than that of celluloid.

set forth.

1. The process,which consist-sin combining with nitrocellulose'a hydrate or hydroxid of a metal, for-thepurpose set forth.- a 2. The process,which consists in combining a hydrate or 'hydroxid'of a metal with nitrocellulose and gelatinizin g the compound, sub- .zstan'tiallyas andfor the purposes set forth.

' l, 3. The process,whichcons'istsin combining a hydrate or hydroxid of v a metal with nitroeellulosefland-gelatinizin 31111600111 pound with a nitrocellulose solvent holding camphorin solution, for the purpose set forth.

' 4. The process,which consists in combining, with 'a solution of nitrocellulose, a solution of -al1 yd;rateor 'hydroxi-d of a 'metal, reacting upon "the compound -wi th a solution of an agent capable of neutralizing the same and precipitating the hydroxid, and removing the nitrocellulose solvent and the soluble cone :stituenrs resulting from the reaction, for the purpose set fort'li.

5. The process, which co'nsists in molecularly combining, with a solution of nitrocellulose, a solution of a hydrate or hyd roxid'of a metal; reacting upon "the compound with a concentrated solutionof a-salt of a metal capableof neutralizing said compou nd, and pre-' cipitating the hydroxid, and removing the cellulosesolyent and thesoluble constituents resulting -from the reaction, for thepurpose '6'. The process,which consists in combining, with a solution of nitrocellulose, a concentrated solutionof a hydrateor hydroXid of a metal, reacting upon the compound with a concentrated solutionof caustic sod a, removing thecellulosesolvent and soluble constituents resulting from the reaction, drying, and *gelatin'izingthe compound, folthe purpose '7. "The process,which consists in combining, with a solution of nitrocellulose, a concentrated solution of a hydrate or hydroxid of a metal, reacting upon the compound with a I IO concentrated solution of caustic soda, remov- 'i-ng the cellulose solvent and soluble constituents resulting from the reaction, drying, and g elatinizing the compound with a solvent of nitrocellulose holding camphor in solution, for the purposes set forth.

' 8. The herein-described product consisting essentially ofgelatinized nitrocellulose and a hydrate or hydroxid of a metal, substantially as set forth.

In testimonythat we claim the foregoing as our invention wehave signed our names in presence of two subscribing witnesses.

CARL GUSTAV HAG'EMANN.

FRIEDRICH 'OTTO CORNELIUS ZIMMERM'ANN. 9

Witnesses:

JACOB ADRIAN,

FRIEDRICH MARDo. 

